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Journal of Materials Science & Technology 2020年第2期37卷 19-25页

作者： Min Su Park Jin Kyu Kim Tong-Seok Han jung tae Park Jong Hak Kim Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Korea Department of Civil and Environmental Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Korea Department of Chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul05029Korea

We report a composite material with the high tribological performance,which consists of onedimensional SnO2 nanotubes(ST)and a high molecular weight poly(vinylidene fluoride)(PVDF)matrix in terms of *** of PVDF in N,N-dimethylformamide(DMF)resulted in a facile penetration of PVDF into the inner hollow voids of ST,leading to the close *** between PVDF and ST results in a beneficial effect on the chain arrangement of PVDF,providing anα-phase with better tribological *** ST incorporation,the friction coefficient decreased by 85.0%to 0.408,and the specific wear rate decreased by 69.1%to 0.412,demonstrating the pivotal role of ST as a self-lubricating material due to a large interactive area and PVDF chain rearrangement.

关键词： SnO2 nanotube Composite Friction coefficient Wear rate

Liquid-like adsorbent assembled by CNTs: Serving as renewable CO_(2) capture materials for indoor air

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Journal of Energy Chemistry 2021年第12期30卷 574-584,I0014页

作者： Jae Won Lee Minjae Kim Han Sol jung Ronghuan Xu Seonggon Kim Yong tae Kang School of Mechanical Engineering Korea UniversitySeoul 02841South Korea

In this study,a CO_(2) capture material in the form of liquid-like adsorbents(LLAs) is developed to overcome the limitations of conventional types of *** increase in indoor activities necessitates the capture of CO_(2) in enclosed indoor *** spaces require safe and stable materials for CO_(2) capture because humans are present in these *** adsorbents are mainly used because liquid absorbents are unsuitable owing to noise and scattering *** LLA,the liquid absorbent assembled by carbon nanotubes(CNTs) is solidified and prevented from flowing and scattering *** present to maintain 95% of initial capacity after recycling 20 times,and have characteristics that can be regenerated in a low temperature heat source(80 to 120℃) and moisture *** work not only provides indoor useable CO_(2) capture materials,but also offers a new prospect in the field of adsorbents.

关键词： CO_(2)capture CNT Silicone oil Adsorbents Indoor air

Finite element and experimental analysis of Vickers indentation testing on Al_2O_3 with diamond-like carbon coating

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Journal of Central South University 2012年第5期19卷 1175-1181页

作者： ZHAI Jian-guang WANG Yi-qi KIM tae-gyu SONG jung-il Department of Mechanical Engineering Changwon National University Changwon 641-773 Korea Department of Nanosystem and Nanoprocess Engineering Pusan National University Pusan 609-735 Korea

Numerical simulation and experimental study of the Vickers indentation testing of the Al2O3 ceramic coated by diamond-like carbon(DLC) layer were *** numerical analysis was implemented by a two-dimensional finite element(FE) axis symmetry *** analysis results gave insight into the fracture mechanism of DLC films coated on brittle ceramic(Al2O3) *** maximum principal stress field was used to locate the most expected area for crack formation and propagation during the Vickers indentation *** results show that the median crack initiates in the interface under indenter,before ring crack occurs as the indenter presses ***,the plastic deformation appears when the indenter penetrates into the *** thicker DLC coating increases the Vickers hardness and fracture toughness.

关键词： Vickers indentation testing finite element diamond-like carbon Al2O3 fracture toughness

Technology portfolio assessment for near-zero emission iron and steel industry in China

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Advances in Climate Change Research 2023年第3期14卷 469-478页

作者： Wei-Yi JIANG tae Yong jung Han-Cheng DAI Pian-Pian XIANG Graduate School of International Studies Yonsei UniversitySeoul 03722South Korea College of Environmental Science and Engineering Peking UniversityBeijing 100871China Faculty of Environment and Life Beijing University of TechnologyBeijing 100124China

China aims to peak CO_(2)emissions before 2030 and to achieve carbon neutrality before 2060;hence,industrial sectors in China are keen to figure out appropriate pathways to support the national target of carbon *** objective of this study is to explore near-zero emission pathways for the steel industry of China through a detailed technology *** innovative technology development has been simulated using the AIM-China/steel model,developed by including material-based technologies and optimal cost *** scenarios have been given in terms of different levels of production output,emission reduction and carbon ***-zero emission and carbon tax scenarios have shown that China's steel industry can achieve near-zero emission using electric furnaces and hydrogen-based direct reduction iron technologies with policy *** on these technologies,minimised production costs have been calculated,revealing that the steel produced by these technologies is ***,the feedstock cost can play a key role in these technology portfolios,especially the cost of scrap,iron ore and *** addition,the feedstock supply can have strong regional effects and can subsequently impact the allocation of steelmaking in the ***,China can achieve near-zero emissions in the steel industry,and electric furnace and hydrogen-based direct reduction iron technologies are crucial to achieving them.

关键词： Steel industry Near-zero emission Cost optimisation Climate change Carbon neutrality Technology learning

Single-step Preparation of Nano-homogeneous NiO/YSZ Composite Anode for Solid Oxide Fuel Cells

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Nano-Micro Letters 2013年第2期5卷 111-116页

作者： jung-Hoon Song Mi Young Park Hye Won Park Hyung-tae Lim Research Institute of Industrial Science and Technology (RIST) Fuel Cell Project Changwon National University School of Nano & Advanced Materials Engineering

Homogeneous co-precipitation and hydrothermal treatment were used to prepare nano- and highly dispersed Ni O/YSZ(yttria-stabilized zirconia) composite powders. Composite powders of size less than 100 nm were successfully prepared. This process did not require separate sintering of the YSZ and Ni O to be used as the raw materials for solid oxide fuel cells. The performance of a cell fabricated using the new powders(*** density ~0.87 W/cm^2) was higher than that of a cell fabricated using conventional powders(max. power density ~0.73 W/cm^2). Co-precipitation and hydrothermal treatment proved to be very effective processes for reducing cell production costs as well as improving cell performance.

关键词： Fuel cells Powder processing Electrochemistry Hydrothermal process NiO/YSZ composite anode

Dopant-Tunable Ultrathin Transparent Conductive Oxides for Efficient Energy Conversion Devices

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Nano-Micro Letters 2021年第12期13卷 437-451页

作者： Dae yun Kang Bo-Hyun Kim tae Ho Lee Jae Won Shim Sungmin Kim Ha-Jun Sung Kee Joo Chang tae Geun Kim School of Electrical Engineering Korea UniversitySeoul 02841Republic of Korea Department of Advanced Materials Engineering Kongju National UniversityCheonan 31080Republic of Korea Department of Physics Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea

Ultrathin film-based transparent conductive oxides(TCOs)with a broad work function(WF)tunability are highly demanded for e cient energy conversion ***,reducing the film thickness below 50 nm is limited due to rapidly increasing resistance;furthermore,introducing dopants into TCOs such as indium tin oxide(ITO)to reduce the resistance decreases the transparency due to a trade-o between the two ***,we demonstrate dopant-tunable ultrathin(≤50 nm)TCOs fabricated via electric field-driven metal implantation(m-TCOs;m=Ni,Ag,and Cu)without com-promising their innate electrical and optical *** m-TCOs exhibit a broad WF variation(0.97 eV),high transmittance in the UV to visible range(89–93%at 365 nm),and low sheet resistance(30–60Ωcm-2).Experimental and theoretical analyses show that interstitial metal atoms mainly a ect the change in the WF without substantial losses in optical *** m-ITOs are employed as anode or cathode electrodes for organic light-emitting diodes(LEDs),inorganic UV LEDs,and organic photovoltaics for their universal use,leading to outstanding performances,even without hole injection layer for OLED through the WF-tailored *** results verify the proposed m-TCOs enable e ective carrier transport and light extraction beyond the limits of traditional TCOs.

关键词： Transparent conductive oxide Metal implantation High transparency Low sheet resistance Work function

Effects of Initial and Boundary Conditions on Heavy Rainfall Simulation over the Yellow Sea and the Korean Peninsula:Comparison of ECMWF and NCEP Analysis Data Effects and Verification with Dropsonde Observation

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Advances in Atmospheric Sciences 2024年第9期41卷 1787-1803页

作者： Jiwon HWANG Dong-Hyun CHA Donghyuck YOON tae-Young GOO Sueng-Pil jung Department of Civil Urban Earth and Environmental Engineering Ulsan National Institute of Science and TechnologyUlsan 44919South Korea Program in Atmospheric and Oceanic Sciences Princeton UniversityPrincetonNew Jersey 08544USA National Institute of Meteorological Sciences NIMSJeju 63568South Korea

This study evaluated the simulation performance of mesoscale convective system(MCS)-induced precipitation,focusing on three selected cases that originated from the Yellow Sea and propagated toward the Korean *** evaluation was conducted for the European Centre for Medium-Range Weather Forecasts(ECMWF)and National Centers for Environmental Prediction(NCEP)analysis data,as well as the simulation result using them as initial and lateral boundary conditions for the Weather Research and Forecasting ***,temperature and humidity profiles from 3D dropsonde observations from the National Center for Meteorological Science of the Korea Meteorological Administration served as validation *** showed that the ECMWF analysis consistently had smaller errors compared to the NCEP analysis,which exhibited a cold and dry bias in the lower levels below 850 *** model,in terms of the precipitation simulations,particularly for high-intensity precipitation over the Yellow Sea,demonstrated higher accuracy when applying ECMWF analysis data as the initial *** advantage also positively influenced the simulation of rainfall events on the Korean Peninsula by reasonably inducing convective-favorable thermodynamic features(i.e.,warm and humid lower-level atmosphere)over the Yellow *** conclusion,this study provides specific information about two global analysis datasets and their impacts on MCS-induced heavy rainfall simulation by employing dropsonde observation ***,it suggests the need to enhance the initial field for MCS-induced heavy rainfall simulation and the applicability of assimilating dropsonde data for this purpose in the future.

关键词： initial conditions dropsonde heavy rainfall forecast global model analysis evaluation

The Association between Fear of COVID-19,Obsession with COVID-19,and Post Traumatic Stress Disorder in Korean Emergency Rescue Firefighters:A Cross-Sectional Study

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International Journal of Mental Health Promotion 2024年第6期26卷 475-480页

作者： yun-jung Choi Heewon Song Red Cross College of Nursing Chung-Ang UniversitySeoulSouth Korea Department of Nursing Chung-Ang UniversitySeoulSouth Korea

During the rapid spread of COVID-19,first responders are at risk of being exposed to COVID-19 due to their role in providing first aid and responding to an unspecified number of *** uncertainty can have adverse mental health effects,such as increased anxiety and *** study aimed to investigate the degree of association between fear of COVID-19,obsession with COVID-19,and post-traumatic stress disorder(PTSD)in emergency rescue *** participants were 150 emergency rescue firefighters working in Region S,*** filled out self-report questionnaires:The data obtained through the Fear of COVID-19 Scale,Obsession with COVID-19 Scale,and Impact of Event Scale-Revised Korean version were subjected to nonparametric statistical analysis using SPSS WIN *** study found a significant correlation between emergency rescue firefighters’fear of COVID-19,obsession with COVID-19,and *** and obsession with COVID-19 were higher among first responder firefighters who were directly involved in COVID-19-related ***,a one-point increase in obsession was associated with a 2.837-point increase in *** on the results,we found that there is a need for effective control of obsessions and fears among first responder firefighters during COVID-19,and we suggest that there is a need for mental health care for first responder firefighters during the pandemic through the development and support of programs to prevent and mitigate obsessions.

关键词： COVID-19 emergency rescue firefighters fear of COVID-19 mental health promotion obsession with COVID-19 PTSD

High-Throughput Pb Recycling for Perovskite Solar Cells Using Biomimetic Whitlockite

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Energy & Environmental Materials 2023年第3期6卷 170-176页

作者： jung Sug Hong Hee jung Kim Chang Hwun Sohn Oh Yeong Gong Jin Hyuk Choi Kang Hee Cho Gill Sang Han Ki tae Nam Hyun Suk jung Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Korea

Pb contamination in aquatic environments causes severe pollution;therefore,harmless absorbents are *** this study,we report a novel synthesis of whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12)),which is the second most abundant biomineral in human bone,and its application as a high-performing Pb^(2+)***(HAP)and WH are prepared via a simple precipitation *** Pb2+absorption performance and mechanism of the synthesized biominerals are investigated in aqueous solutions at neutral *** results demonstrate that WH exhibits an excellent Pb2+absorption capacity of 2339 mg g^(−1),which is 1.68 times higher than the recorded value for ***,the absorbed Pb^(2+) ions are recycled into high-purity PbI_(2).This is employed as a precursor for the fabrication of perovskite solar cells(PSCs),resulting in a conversion efficiency of 19.00%comparable to that of commercial PbI2 powder(99.99%purity).Our approach provides an efficient way to remove Pb^(2+)ions from water and reuse them in the recycling of PSCs.

关键词： Pb absorption Pb recycling perovskite solar cells water purification whitlockite

Stabilizing lithium deposition within bimodal porous SiO_(2)-TiO_(2) microspheres as 3D host structure

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Nano Research 2024年第11期17卷 10179-10188页

作者： Noeul Kim Jae Hun Choi Min Kim Dae Soo jung yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seoul 136-713 Republic of Korea Energy Storage Materials Center Korea Institute of Ceramic Engineering and Technology Soho-ro Jinju-si Gyeongnam-do 52851 Republic of Korea

Three-dimensional (3D) host materials for lithium metal anodes (LMAs) have gained attention because they can mitigate volume expansion and local current density through their large surface area and suppress the dendritic growth of lithium. Recent research on 3D host materials has focused on conductive materials;however, the benefits of 3D host materials cannot be fully utilized because lithium deposition begins at the top of the structure. Herein, we fabricate SiO_(2)-TiO_(2) composite microspheres with bimodal pore structures (bi-SiTiO) by simple spray pyrolysis. These microspheres effectively store lithium within the structure from the bottom of the electrode while preventing lithium dendrite formation. Focused ion beam-scanning transmission electron microscopy (FIB-STEM) analysis reveals that the lithiophilic properties of composite microspheres enhanced their effectiveness in storing lithium, with small pores acting as “lithium-ion sieves” for a uniform lithium-ion flux and large pores that provide sufficient volume for lithium deposition. The bi-SiTiO composite microspheres exhibit a high Coulombic efficiency of 98.5% over 200 cycles at 2.0 mA·cm^(−2) when operated in a lithium half-cell. With a high lithium loading of 5.0 mAh·cm^(−2), the symmetrical cell of the bi-SiTiO electrode sustains more than 900 h. A full cell coupled with an LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) (NCM811) cathode also exhibits enhanced electrochemical properties in terms of cycling stability and rate capability.

关键词： lithium metal battery spray pyrolysis three-dimensional(3D)host materials bimodal pore structure lithiophilic materials